I will be including a level 9 published adventure in my campaign soon. The thing is, the four players will be somewhere between level 18 and 24 when they hit the dungeon.
Aside from obviously scaling ...

Most encounters are scaled down by removing monsters from play. However, solo monsters are designed around a 5 player party.
What is the best way to scale them down to be an interesting fight for 2 ...

I'm eager to hear how other people handle this? I do quite a bit of GM-Less gaming in Mythic and some other fringe systems, but, sometimes it's just better to be playing 'other sides' even if you're ...